Table 7.

Regression of the effect coefficient of in-hospital standardized sales/volume of sales of drugs of selected supply varieties for centralized procurement

	Regression (1)				Regression (2)
	Effect coefficient	Robust standard error	t	P >|t|	Effect coefficient	Robust standard error	t	P >|t|
Difference (1)	-0.42	0.14	-2.98	0.025	0.49	0.09	3.11	0.021
Difference (2)	-0.13	0.12	-3.45	0.014	0.57	0.06	3.81	0.009

(i) Regression (1) is in-hospital standardized sales ($); regression (2) is in-hospital standardized sales (DDDs); (ii) Difference (1) is the selected supply species; difference (2) is the unsuccessful supply species; and (iii) the study takes the natural logarithm